let m = new Map([['bj', '北京市'], ['ha', '河南'], ['hn', '湖南']])
// console.log(m)
// console.log(Array.from(m))

// let arr = [...m]
//console.log(...arr)

let m2 = new Map()
m2.set('s1', 100)
m2.set('s2', 200)
m2.set('s3', 30)
m2.set('s3', 300)
console.log(m2.size)
m2.forEach((value, key, map) => {
    console.log(value)
    console.log(key)
    console.log(map)
})
console.log(m2.get('s1')) //100
console.log(m2.has('s5')) //false
console.log(m2.has('s4')) //false
console.log(m2.has('s3')) //true
//判断有没有200值
console.log([...m2.values()].includes(200)) //true

console.log([...m2.keys()])
console.log([...m2.values()])
console.log([...m2.entries()])

